Overview
Langfuse — Open-source LLM observability platform
Langfuse is an open-source observability and analytics platform for LLM applications. Trace every prompt, measure quality with LLM-as-judge evaluations, track costs and debug issues in production — self-host or use their cloud.
LLM call tracing
LLM-as-judge evaluations
Cost tracking by model
Prompt versioning
Features & capabilities
Everything it does, in plain English.
FeatureLLM call tracingIncluded
FeatureLLM-as-judge evaluationsIncluded
FeatureCost tracking by modelIncluded
FeaturePrompt versioningIncluded
FeatureSelf-hostable open sourceIncluded
API AccessProgrammatic access available for developers.Available
PlatformsCloud · Self-hosted
The honest take
Where it shines, where it stumbles.
✓ Pros
- ✓Open source
- ✓Self-hostable
- ✓Strong evaluation features
! Watch-outs
- !UI less polished than paid alternatives
- !Setup required for self-host
Who it's for
Where Langfuse pays for itself fast.
— Use case
LLM app debugging
— Use case
AI quality assurance
— Use case
Cost optimization
Community reviews
Share your take on Langfuse
Sign in to leave a verified review.
J
★★★★★
1 months ago
Best in class, no question
Worth every penny. The recent updates have addressed most of my initial concerns. The free tier is genuinely generous compared to competitors. My team is very happy with the results.
M
★★★★★
1 months ago
Outstanding experience
Exceeded all my expectations. The accuracy has improved significantly with recent model updates.
A
★★★★★
1 months ago
Worth every cent
Can't imagine working without it now. The recent updates have addressed most of my initial concerns. The free tier is genuinely generous compared to competitors. Best tool in this category, hands down.
L
★★★★★
2 months ago
Changed how I work completely
Can't imagine working without it now. The recent updates have addressed most of my initial concerns. Reduced the time I spend on this task by about 70%. The recent updates have addressed most of my initial concerns. Will continue using this long-term.
R
★★★★★
2 months ago
A must-have for any professional
This is exactly what I was looking for. The interface is intuitive enough that I didn't need to read any docs. Works consistently across all my devices and browsers.
K
★★★★★
2 months ago
Worth every cent
Exceeded all my expectations. I use this daily and it's become essential to how I work. The interface is intuitive enough that I didn't need to read any docs. Looking forward to seeing how it improves.
V
★★★★★
4 months ago
Exceptional quality and value
Seriously impressive. The free tier is genuinely generous compared to competitors. The recent updates have addressed most of my initial concerns. I use this daily and it's become essential to how I work. Will continue using this long-term.
N
★★★★★
4 months ago
The best AI tool I've used
Can't imagine working without it now. My team adopted this immediately after I shared it with them. I've recommended this to at least 10 colleagues already. The interface is intuitive enough that I didn't need to read any docs. Keep up the great work, team.
C
★★★★★
5 months ago
A must-have for any professional
This is exactly what I was looking for. The accuracy has improved significantly with recent model updates. The customization options let me tailor it to my exact workflow.
A
★★★★★
5 months ago
Exceptional quality and value
Absolutely love this tool. The collaboration features are genuinely well thought-out. I've recommended this to at least 10 colleagues already. The accuracy has improved significantly with recent model updates.
R
★★★★★
7 months ago
Blew away all expectations
Game changer for my workflow. The accuracy has improved significantly with recent model updates. Works consistently across all my devices and browsers. Will continue using this long-term.
J
★★★★★
7 months ago
Has potential, needs polish
Average experience, average results. It handles edge cases better than anything else I've tried. Performance is fast — no noticeable latency even on large inputs.
C
★★★★★
10 months ago
Impressed with the results
Genuinely useful — glad I tried it. The recent updates have addressed most of my initial concerns. I've tried 5 similar tools and this one is clearly the best in class. Customer support responded within hours and solved my issue. I'd love to see better export options. Looking forward to seeing how it improves.
K
★★★★★
10 months ago
Blew away all expectations
Exceeded all my expectations. The accuracy has improved significantly with recent model updates.
K
★★★★★
1 years ago
Changed how I work completely
Absolutely love this tool. The outputs require minimal editing — saves so much back-and-forth. Integration with my existing tools was seamless — no friction at all. I've recommended this to at least 10 colleagues already. My team is very happy with the results.
H
★★★★★
1 years ago
Does the job well
Does what it promises and does it well. The accuracy has improved significantly with recent model updates. The UI takes some getting used to. Would recommend to anyone in my industry.
M
★★★★★
1 years ago
Blew away all expectations
Game changer for my workflow. The accuracy has improved significantly with recent model updates. Customer support responded within hours and solved my issue.
W
★★★★★
1 years ago
Exactly what I needed
Absolutely love this tool. I've recommended this to at least 10 colleagues already. Customer support responded within hours and solved my issue. It integrates well with VS Code / Slack / Notion — my daily drivers. Would recommend to anyone in my industry.
M
★★★★★
1 years ago
Exactly what I needed
Best-in-class, period. Reduced the time I spend on this task by about 70%.
Alternatives
Similar tools worth comparing.
Harvey AI
AI legal assistant for law firms specializing in research, drafting, and contract review
Cerebras Inference
Cerebras wafer-scale chip inference — run Llama models at 2,000+ tokens/second, the world's fastest AI inference.
Anthropic Claude API
Anthropic's API for Claude models — build AI applications with Claude 3.5 Sonnet, Haiku and Opus via a simple REST API.
Supabase AI
Supabase's AI features — vector embeddings, pgvector search and AI SQL assistant built into the open-source Firebase alternative.
Groq Cloud
Groq's LPU inference — the fastest LLM inference in the world, running Llama and Mistral at 500+ tokens/second.
Qdrant
High-performance open-source vector database written in Rust — fast, accurate and production-ready for RAG apps.